The trading desk hours are from Sunday 5:15 PM (EST) through Friday 4:00 PM (EST), subject to available liquidity. Although trading is closed on the weekends that does not mean the market cannot move. At times the closing price on Friday will not be the same as the opening price on Sunday. When banks begin to feed prices to FXCM the Trading Station will begin to update rates. rior to open and using those rates, FXCM will conduct a sweep of all outstanding orders left open during the weekend for any that would have been triggered. For your order specifically, the best bid prices for the GBP/USD pair was 1.7639 at Friday close and 1.7783 at Sunday open. Your limit entry order was set at 1.7720 which fell in the range between Friday close and market open. Subsequently, your order was filled at your requested price as there was a counterparty willing to accept at that level. lease be advised, limit entry orders are not market orders and they are filled at the requested rate or not at all.